SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96587493f8687b6020271ba6af2ec64985b3b1b268e2ba10b54d2794276dd940' 
  AND token = '7OTUCvGM9rzfEPxOLydvZIfX4KCsoWSZJ/SMXm/ronY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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