SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e552d95172271cf05fe4059e470a6786c11d7b89b839c1fbaf3e2678cdc67dd8' 
  AND token = 'hiUR2lyVuZjWjXerOZbiPeMRuaAR9HtAZHrZmDSB0Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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