SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36edf9696ba282bdd536f0f37180aa5064cfd5011bf0163d8de41d67ff4abe07' 
  AND token = 'ETfuC5SpeDBZSKR1tuIXaatm2iGBa+Fxm0lbYGsFj9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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