SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d011a6d092479b651c553130d9b2e31a65d0a2dada314716af094a611b7bf80' 
  AND token = 'BBxkgjC6xXyxbx/amAIacs44s6pS1tPGSrsgJbLCFzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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