SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfb34c2bd1620c4d26b007138088fc1752d69aa10c77a552d6d649e8b6028177' 
  AND token = 'YLuwcEWhYPrdmvEMiJi/DR38fXJL7GiGEo7jZhkIiKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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