SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9306bcea7515e6429f31c1043cbb05e934733e37a5a3a649151f513609189a15' 
  AND token = 'mzHjlUcFqkb/oBHL9Kl/im5CQAQc6qTIwzwpE5no3go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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