SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87bcb037be7f6d2db9d4dc12a114ae9280019a6148e292087631d4ff45cb8fc1' 
  AND token = 'lYB1s6Y4olFfx8XTRtTfdMxAA95WZNmohy0FceRrT6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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