SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57d0e10d63336a66e131e84f735107ce5be8abe80626fc5935dda71152db7a21' 
  AND token = 'QbpdX21wY+lhZ2gQRfIzd/V+wDZMkNkv/uC9/wMF2ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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