SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8f2c6ffe0f9f705e5398c4aa75da60c08554f23ace4c24207543bf7fca5b125' 
  AND token = 'ptKMCIsYbzh3AAJlSMKcusocB1nFlOoqWe21iJSuR8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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