SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fff656e2d0b32f26281a818aa8b64976bc1c22de1939500f7453fe15915c3892' 
  AND token = 'nZIIwBbdmMN6pJ/ZIU3viebOwm5GVBNg7c5sE3OgZjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00106

JSON explain

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