SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a81bc732efd9384dd2bede56551e5d95a3bf3027b2e1850e0516038e6e359160' 
  AND token = '5gphaQCMA/w17xLreCL0SyD8/CfLMP5YB6mvimAwUMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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