SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af1d1ce08ff98a1662d8fef2511e726e3c7bce75c7738797fb064ee49eaaa1d' 
  AND token = 'U0RWxWbl+tjpkyuC9nU3re2pF7JENK/yIgzXtu4JNUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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