SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '002f0e8fc20e045fae63459bbb66744b286832badcb966fe2535e84ae467a01f' 
  AND token = 'kPPgkMA5hNNCrqpSvhO6K3nJV6qimHIjNnMd3LTx9PY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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