SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18e0b15ca33cc539105dae0f6eca49c36d247907a3623cdf04e0aad363110870' 
  AND token = 'za7AVgI8CFmOLOb65If5FfK2TJN61nClZwShUNjQIwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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