SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8a1d16f66f25148217475d138f5b5881faeab5747b556ed74583f98bda567ed' 
  AND token = 'XksZRXLcpakH2p5F/Sg8joPkalXXOoh4QcYNLDp+EGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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