SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575b77a1ec75011a74d47865a8bd98919d46cdbc694c14b8a539dd995a19bdb1' 
  AND token = 'S5Odt1mjp/TydnREvBoYmoPvWOw+EoRzou/IjZU4iag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}