SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '069b4b7fddf657b955ff446a1e29d3998a37acdecc2f7e2b487744786bcdad9b' 
  AND token = 'XG7AkjnvYhQ6K6/CssGZVHIaRU4wq6AOx2RyPT9D3qY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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