SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c2173899e8a77e509e9dc698b836e5ffb387508d4a3476878bbb58d2f275ae43' 
  AND token = 'QquafiGROS2jJOcuTyFA4YPJS2thxLw+QkftIIDupSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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