SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1310b85d14d92326a9de99164798bb2e61f7472b96f7c328b8d021e58142075' 
  AND token = 'Rv+aofO/f/XIkIvESAU1VcqNsfbwBihOTJcuFPgEkOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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