SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38108b5b40257a9ccd42dcac2861623c020f77526cc2fa5a6060903ce4460d61' 
  AND token = 'p/zdeGPyYkcO1vyXBNOaYcDlyDTPdnKjthGbPU4hW1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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