SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43808c77b0d142dfd921a4485175c68183e25f991a6dd63ab969b39219085651' 
  AND token = 'JkgnLjFvEf4JahfKZldgLICrsAScGdmb3K5gTtIXu90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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