SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c14690e54a0f9a879812c44ee8dc9d754e43b430e523cc047f7fc4265131668' 
  AND token = 'uXTYJJ7AmuUR3G4Wk9LfxA9c2w2fXQbvUAESLzZy5dI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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