SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e21b643278ee38f9593d8c23419426f8da33f71fa1d19899315ff6e1604116f' 
  AND token = 'UeJQgcDI208OcvuMyHELAHvJIBogrwbBkNoBLS1fGaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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