SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bcac0234cf84b501e6c52cea25c9ec1e11545d809d1b04046ab06ba4dc62533' 
  AND token = 'VRRA4K99OTUSjRFFBMuWUZcqrmg5xythjtVXbfRjPZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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