SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a442679c25ce65dc6188095f3807b36ae1a95387f6969f8cbcb9296c5e03d9a' 
  AND token = 'pLpzwp1HSQjrUPcphvRVNn5PLr5m2pOl9+rGtEAKXOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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