SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9583376dcb6d3cfa097e52c8e961eaba693155383f64781817338080fa54e2ee' 
  AND token = 'xewcpD5awdhl2miQIkckex3t5Dxntzgmd8cJelB4hsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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