SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba34f79bbf4700b19cc28ec7f1a9f200260f693f76a9b064cb1ea6326b20945e' 
  AND token = 'WbhJG5iKEP7q4pqB5944ub9YfH709GFkdpA/vnOW8Ko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}