SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac1ce72eaed9e0d9e6d35e7250758ad6bef952139680ebf69e1bf8140dd58ea4' 
  AND token = 'Ha8ZpBNMxwPoSZPDJL8f62vRgSLbJxz3+N994iyiEzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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