SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '462d2b54696ac35732b51a86f14af30128a29670293b6d6232395e475b222db1' 
  AND token = 'GluS3YuLLZpe9jCmqfFid7wkgsCS+cH0kzuVFLFDQws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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