SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b801cdbc5a967d9d229ecd837d8fda19b4a621367acf91f34a6b2a79cc58a5d7' 
  AND token = 'HxwJUwruYdbvmVbFAcpeA8T0P7p5uAiuFl1yjTBk/Uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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