SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c6dba71cea2b2b32375370ab4fc32c1fe52bcf064f03db2243a7595d08d1d263' 
  AND token = 'LzbV6IhxfpoFxdQ6+7elgsOKF18BVCgjSgoRAC/DVKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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