SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a35554bfb1748b7b18837cc38140b7820fb2c013eb815db14af8fd27bc69fa4' 
  AND token = 'E54bqs/zTCbx2cadcuu6ctObdOC/T1Rd2JO8hECK2V4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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