SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a89cc81435e151854e929a042db88f36df7291be5e81e765bd592efdf443378' 
  AND token = 'ETecGj8zo0Bwag2jPfxemL2ImiBsSsZtJbNcTmVtx84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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