SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd6eadd237eb7fcc69e489ab9124dc892faef952bbed90430d0d300a42034de96' 
  AND token = 'S43sBCBboyIu4FxqC5K/mi4E4kPldJvvyXDiE3BOD00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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