SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dad1934a2e567f4c6b54f20eed53d7d40deec2e52b592b6b7ba7a8a65a78f30e' 
  AND token = 'VoIgqDij5IL2No6NVY1lsZRzVgTUrBwnKHX989FWalc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}