SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21262c486bb4131c913ed46389c79420f3be907ff442979aef277e08c70b8411' 
  AND token = 'kypFFcEvOT9ZhxYbwEd1qLcPVRCjmHPBWI6hllQv3ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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