SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06ccd586066da8465451b55758d92744761b36240e7cf0085a37b3dc29b9fc2a' 
  AND token = 'Tpao8EQKu3EkLk6r7XAKQxmE7+jrETfPTf6gVsyvc5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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