SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fc8ea4c312a46b085963d7ed98188d617c29139c7a0c177f9dd975719bc1070' 
  AND token = 'l8GPG8w+VwthwDcnQJiVfeDCn9HR6A7Fl3jyjwT0FlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00097

JSON explain

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