SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2502e55a60e1f97ea2c5b6293cbaeae30b26a4d8629dd804bd187b55af42dab1' 
  AND token = 'U+/N/iDQ5YwXBD34tt8/BgK9EO+TxWHHF9zNst53Clw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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