SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8912fb5dd89429b2434c81949b90cf82d659fea7525a070619a2be40374c883d' 
  AND token = 'wAqyv+q/3SNFhEkLBmjk2PUx4XjCHq6NGD3SOh6Gdb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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