SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e6732069286af31033326988592fc026182977e30be693ec218789ca602699e' 
  AND token = 'nz2YdxnYxiKDRurxkO2cWpWt5KZGd9+XjfR1F83Pfro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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