SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad4b0162db1d1c535a15e7734f0616cd08b4763f897e8c662d0b2369bc07049e' 
  AND token = 'Q8eyzVN56IqCJxfgxNgZS5agVmM9xMpFhLFQmYUCBdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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