SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ae5e4acf5f39928cddbbc9e4babafe0af641a4837c08e8ed6d2c86d790741fc' 
  AND token = 'AqVIakMOzTZbwnn15vHOmkhya98h26Uk9tO8kiYvURQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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