SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b25661668faffb031eafb01a3e096927b427a8a0b77be59ddbc0624c05688ff' 
  AND token = 'd5lgeUrDg2uwKyTHlR2o26JQ/Byz4LnCuw8+mDx3Gos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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