SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54bc9fffceea7e283fb5ec8360b7b1b642e679c69788115643db272425f5d732' 
  AND token = 'l1/I1BqJ1JwU9z4gARzzctQvE1cy6z8fbgPIVq7jKrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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