SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c55cf7f9d2e84193b7a24a7e26be01012f473ff0e7af81df9caaf65424a4a58a' 
  AND token = 'e2s2jk89SdtJXL9smw87a3LDGOQ3pBsLkNUkyGZc6wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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