SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb656673a33f6d9297038fd3d2543e207460d9e15abb085311cc463341189d9' 
  AND token = 'cNAzOWbo213GkFoV9Q/3iWT0fq8ztDWgioSRNHTs/7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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