SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '546498c75fde797a3bfa897d2e31bd32a13c70822627ed12a665c0f1b3f74359' 
  AND token = 'l0vXMABNOO9I8PDb6UvCrz0zWYX8pd06pIVwrZLqDVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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