SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac9c24feed5a43f39847b3ea010f637f14d2ac6af78af057f0f641c5d3ff8b8b' 
  AND token = 'P6SCdURXduo6j/oLmqCIlJoBvAZ7npFHSmKM7z8BHRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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