SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85696d3546796290dbe387f9dbec147b255e6b2bbade07f7dce151ec287c5924' 
  AND token = 'nROurygC+NTCVf944jhlqzYcokqi5xGiSbX/7EPJWaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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