SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f4031529f4294c94ee4991df197ead3b6289888c4b49517f0e5290edfdd45f9' 
  AND token = 'mJGCBOYZ5ioOFEL5cdZLmGR1hqXNu2OwrVrtxyaenRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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