SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bfc0426894c52d7cf35422add5036ef3e667a746f8e7e2f57fd09e2de752b1c' 
  AND token = 'jN1vNfCGKOoOTodV6PfhjWWXnftXfKIVi/x6eWE/bzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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