SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcb46469e7cdb75db7702425fd609b3a9fd56f039b778838090c936e116bed76' 
  AND token = 'fc/FPv0pT3rs5PPqBf5Jhw2Fqqpx7bFy0SBncxWRmcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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