SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae8fecde2cbd9821579b07a875ccf63c13797d883d95cd09ed1dd8796a8135ed' 
  AND token = 'u2Fs3MRhVnUuqRyicj/92yorBTqj/jIX6ScDz4gpi2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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