SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e4c11db8e3732f5aca08fbbaa966e50bfa314b46ca7021f9a7ced9807d20418' 
  AND token = 't4hF7sPl281AB3TdZkce863DqvZ11GFnyMSUvrxFqTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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