SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '249ed5a6e8d356b41c0b40c8911fef363aaa90df3fc5f25859889cac12cb97cf' 
  AND token = 'jGWt5JEeYIVRm1LBTY5IsPQZvGdo6wy/FtCUooAZC4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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