SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0aff64313d149a40aa36e24aa1035a465af415646580a0d69e71cbad53c089c' 
  AND token = 'tTRO+Np4Cwwmzq0/ioeYkyCKqbzk5HnxN9A7pWQ3I3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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