SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b45d7f9fdc75aaecc5ea1f13b4eb23961b0ca25059ba59fb475b2ca24fbdf58' 
  AND token = 'OVVkX70BA5U8JM592gkpLrdrSW9BZ6L4APaFCePmoWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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