SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f3f6eb1d9989d446a9d39dd3184f8908b2690cee876d82f1363497780181330' 
  AND token = 'w7HwMBf3wExnj8947Lx2MTWyYVD/f+pMTG6Uk+CmL6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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