SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461861f72d385a4b8ef67310dc8f8e351994b14788f2e97241aff1cd5977827c' 
  AND token = 'RiPUeFuy7s8Fjy9aquVLAN0oD9Jh9rQSQZ8Y64IQ8tA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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