SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f1810841dad00d24194c43817c558fe0e87c32e3f25ef34a981e5b5f734ba2f' 
  AND token = 'QqBZ9YSarZFZRtZ8xc8zQX/DB/oKdSbXCglUstfGE9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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