SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '325252db701b29897cd73fc01950644608bcab21a492dab1aa4eb10f5b6810a8' 
  AND token = 'TtT5W2W3AgePXvP/mjS5Dl8oTaIEJeXav/eK8ACYCbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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