SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72c798bfe1834b28cb4cf4eac796a347cb43ad79c77b5edc9975fa0e6232d1f6' 
  AND token = '3AaYgLyk+ofsnzXD+VbqcM8X5pt9nV86UOK7cZR5O/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}