SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e1335eb38f6ac1f842aeb9629629b284c70deae33aa4052846ffde8187abc47' 
  AND token = 'jVwA35mZ9i9LKiWgZ+KNNczwcqvk9hNW+j151snbo14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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