SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef43c927fac8f20bab45d418f9a27702f99665052a93d94ef6601f71ae5af773' 
  AND token = 'ItHeJOP5v5jRL0Allr7YSNPGc9CzSRjHVqssl5I2P18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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