SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4facc78339d31bb37a7912b951b7ea767554282d760535a6627123e944e29cce' 
  AND token = 'aFuLS38kyRM27DqWPz0wljC/FZIFEDbViKAe3b3SQ/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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