SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbdaec396e2f26574eaf8c8f673ce7a3bc443774d6271ebb8c44f89c0c56a756' 
  AND token = 'gztvklBFy5gi2JATj+m5nAkeM+DJfYVGqNfUR0PlRko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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