SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd710f41b785bb41368e2403b1370b77931d7ffe339bc727c8a8f9c232b1b22dc' 
  AND token = 'u02p+rcBimml58jYIg6sOkrvFvBEYEOAhiGp9rjZ2jM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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