SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ef4cea90f8970d48643386bcd0113930e0eaf6e4a18682b12494f0406139583' 
  AND token = 'nIzivsYln4UNvxc5bp7i6VffuKy4tM+pc22Ij8zfwTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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