SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96fad6873c01ca24cc3db41f96d13fadc9fc66662cea2717d00b19a79da13553' 
  AND token = 'o3nKIEysJ9FWgZaskLntUGJcPXrhcfVBDTKzMIvhezQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}