SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caef6dac90b9bcfb7b7ecfadb042911f10a469b2cb2abec1e4a2203adb5ae611' 
  AND token = 'La9GsSFTR649c1Tnk86+xYCBoOU5bJ4RZK8rvdOcBvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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