SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0feca905703da365a66fe327a6e74f9f8292efe9158f4cbd34852256422616d2' 
  AND token = 'rGuB7Kk13IMPhzOjKKXwU451u1CpTB+cj1Yl4jYjwYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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