SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02e1815aef59abcade4919a27f41334bbb90392288b22e75cba1aa06156263d6' 
  AND token = 'Rt5JX89Vd38xLwCYmmFTZyvwg/CFpMrAoYETgXOzYso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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