SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f480dba7ad09fc9f786cbe3b4b22bde6004eea614034a988acd341aff714351' 
  AND token = 'Dd7nY4o4NBxePrFlmvJGscJRSIkd6lYlvXM4mfCTn5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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