SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f97a03f3a1c0423df138dc6f21b9de23dc0cdb2961bb9663582ab092fc9a19b0' 
  AND token = 'k9+PBbcxsg5dOZqNbCUKVG8epzWJ7w0/xYoLHjk0w6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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