SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74be0f20869241b991cf05c2f3bbb3a858d128b1a7190a4130e7903570aedfc5' 
  AND token = '/p8MwjP57mtwbadosHQKDG7ay0XymQTXPtFMnzZn1DA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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