SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94b024c59f33354396779b3abfa04c4848db26e063272c3553ed62b8c24a4025' 
  AND token = 'px6c4HMtjFD8JWBIuaULaoJbH8kE9umxqNSlMhaNxpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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